|
Effective crime control using GIS
Crime pattern theory:
As offenders move through routine activities of home, school, work, entertainment (shopping and recreation) they develop knowledge of the paths to their routine activities as well as areas around routine activities (personal awareness spaces). Different offenders may have different awareness spaces which may overlap. Generally, motivated offenders will discover potentially good target areas which offer a good choice of targets and low risk within their awareness space, although some will seek out uncharted areas Consequently areas within the general urban space that are part of most individuals selective target areas will have the most numerous crimes. Hotspot identification using GIS The non-random spatio-temporal distribution of crime suggests the existence of clusters or hotspots of crime in space and time Sherman et al. (1989; Sherman 1995) found that in Minneapolis of 323,000 service calls to police in 1986, found that a small number of hotspots produced most of the crime in the city (50% of the calls came from only 3% of the locations). A crime hot spot is generally defined as an area containing dense clusters of criminal incidents. Identifications of hotspots helps public safety institutions allocate resources for crime prevention activities. This geographical analysis is usually made based on crime pin maps of reported crime events over a certain period, Before the recent technological advances, law enforcement agencies typically placed colored pushpins in wall maps to visualize individual crime events and examine the spatial distribution of crime locations. This was a popular approach for detection of crime ‘hot spots’. Now this can effectively done using GIS, it permits the analyzers not only to draw the hot spots but also allow the analysis of hot spot over a period of time, the location of hot spot on week days for motar vehicle theft for may be different from that of week end. Geo-coding is necessary for generating the GIS based hotspot maps, it assigns an x and y coordinate to an event, or address, so it can be placed on the map. This allows fast and accurate visualization of data on the map.  The homicide occurrences on the map of Homicides in Washington, D.C. in years 1994-95 shows geo-referenced locations of crime data |